EPOC: The "Loch Ness Monster" of Fitness.

Invariably, when people find out I'm a personal trainer, I get "The Question."

"What exercise can I do to lose weight?"

The answer, as with most things pertaining to fitness, is complicated. The two more concise and definitive answers are "none" and "many." Now that I've really muddied the proverbial waters, I'll try to explain the situation in more depth.

To begin with, it's important to understand who the person posing the question is. That's really the crucial element in the equation. Put differently, I've rarely been approached by triathletes looking for "fat-burning" exercises. Most of the people inquiring about a weight loss regimen are individuals trying to find their way back into fitness and health. And that's a very important caveat.

So, to reiterate, a person struggling with their fitness approaches me ands asks me about the optimal exercise for losing weight (fat).

The answer I give them, unfortunately, is.... "there isn't one." The average person is essentially seeking the "Loch Ness Monster"* of fitness: the "one" exercise that will magically transform their middle-aged spread into abs of steel. Sadly, that exercise doesn't exist.

But there are still "true believers" who insist that they've seen a few humps crest the surface of that fabled murky Loch. And, similarly, there are people that have tried (or want to sell you) a regimen that they swear will magically melt the pounds away. They've even given it an official acronym: EPOC or "excess post oxygen consumption."

What is "EPOC?"

In very general terms, "EPOC" correlates to the amount of calories you burn post workout. Most articles and studies addressing EPOC suggest the best way to achieve an elevated metabolism post-workout is through anaerobic workouts (i.e. sprinting and High Intensity Interval Training) rather than the traditional aerobic workouts such as walking or swimming. The principal difference between the two training methods is that anaerobic exercises ("without oxygen") are much more intense than aerobic ("with oxygen") workouts and involve maximal exertion and effort.

In an article for "Health Essentials" by the Cleveland Clinic, Sports medicine physician Michael Dakkak, DO, compared EPOC to the heat of a car’s engine.

“After you turn off your car, the engine stays warm,” Dakkak said. “Your response to exercise is similar. When you finish a workout, your body continues to burn energy as part of recovery.” (1)

This seems like a very apt and succinct analogy ...albeit for a select number of people. Trying to grapple with the science behind EPOC is tricky, because, well....Nessie. There haven't been many actual sightings — or, in this, case, studies. But the ones that have been done exhibit many similarities. I'll list them chronologically.

The Studies

A 1992 study for The Journal of Strength and Conditioning Research detailed the post workout metabolism boost as it pertained to various high intensity workouts.

The study showed that the greatest post-workout metabolism boost (measured one half-hour after exercise came from heavy weightlifting (51 calories) followed by circuit training (49 calories) and then cycling (32 calories). (3)

Look at the criteria: cycling at 80 percent of maximal heart rate for 40 minutes and 40 minutes of heavy lifting at 80-90 percent of the repetition max (RM).

Who is going to do that?

Not your average sedentary person who sits in an office chair for eight hours a day, and then comes home to a big meal followed by binge-watching "Game of Thrones." So, the numbers are completely irrelevant to the majority of the population.

An oft-cited PubMed study on EPOC titled "Effects of exercise intensity and duration on the excess post-exercise oxygen consumption," had this kicker at the end of the article:

"The earlier research optimism regarding an important role for the EPOC in weight loss is generally unfounded. This is further reinforced by acknowledging that the exercise stimuli required to promote a prolonged EPOC are unlikely to be tolerated by non-athletic individuals. The role of exercise in the maintenance of body mass is therefore predominantly mediated via the cumulative effect of the energy expenditure during the actual exercise." (4)

To paraphrase: the effects of EPOC are dubious, and, even if they did prove to be consequential, the amount of exertion necessary to accomplish it would rule out a majority of the population.

Lastly, a 2015 study revealed its limitations right in the title: "Caloric Expenditure of Aerobic, Resistance, or Combined High-Intensity Interval Training Using a Hydraulic Resistance System in Healthy Men." (5)

Once again, the subjects of the study are young, healthy, and active men. You would have to match that criteria to perform the aforementioned exercises at (or near) maximum effort and heart rate. So how is this germane to the everyday individual? Bottom line: it's not.

Conclusions.

So, is there anyone that can benefit from EPOC? Yes, as seen above in the studies. If you are already conditioned and accustomed to vigorous workouts, your daily regimen can result in a post workout "afterburn." But that pertains to a select percentage of the general population.

My recommendations for the general population are to start with a consistent low or medium intensity regimen, adjust your eating habits, and temper your expectations.

The first set of criteria is pretty self-explanatory. If you've been sedentary or inactive for a long time, jumping into the latest HIIT workout will be detrimental to your goals and, quite possibly, to your health. The chances of deconditioned people enjoying a sustained maximum heart rate workout is approximately zero. Furthermore, the concomitant chance of incurring an injury during the workout is very high. Instead, start slowly. Walking is an excellent low-impact way to get back into shape. And cut way back on the sweets and especially the booze. Those are two proven ways to cut fat and get healthier.

Secondly, and equally as important, be realistic about the fat loss associated with getting back into the fitness groove. Fat loss takes time and commitment and is incremental. In the initial stages of reacquainting (or acquainting) yourself with fitness, it's helpful to focus on the myriad benefits of movement, including weight stability, mental and emotional health, and functional fitness gains.

Eventually, once you've established a consistent regimen, you can up the intensity and duration of your regimen, and start to reap the benefits of EPOC.

*Tying things all together...

Ever since I was a kid, watching the grainy black and white images of "In Search Of" with Leonard Nimoy's baritone narration, I've been obsessed with the Loch Ness Monster. About twenty years ago, I did a cycling trip through the Scottish Highlands with my buddy Cash.

We rode about 50-70 miles per day, often in inclement weather. (My buddy Cash lives in Southern California, and he quipped that he "needed a vacation from his vacation.") We used Fort Augustus, on the outer banks of Loch Ness, as our home base. On our first ride, we rounded a bend, and Urqhaurt Castle appeared out of the mist. It was every bit at hauntingly beautiful as depicted in the TV show.

As achingly beautiful as the scenery was, the food left a lot to be desired. (Although, recently, the Highlands has earned a reputation as epicurean destination.) Everything was deep-fried, including candy bars. And I never quite took to haggis. All the cycling combined with the bad food and a protesting digestive tract led to me dropping about twelve pounds on my ten day trip. I'm convinced that trip reset my base metabolic rate for weeks afterward. It's not a method I recommend, however. Very few people like the combination of rain and bad food. Even if Nessie is involved.

Sources:

(1) "What is EPOC? (And Why It Matters.)" Cleveland Clinic "Health Essentials." (10/23/2023)

(2) "In this study, metabolic rate was measured by indirect calorimetry for nine volunteers after 40 minutes of cycling (80 percent of maximal heart rate), 40 minutes of circuit training (50 percent of individuals' maximum lift [1 RM] × 15 repetitions × 4 sets), 40 minutes of heavy resistance lifting (80 to 90 percent of 1 RM × 3–8 repetitions × 3 sets) and a control interval. Weight training included use of eight stations of Universal multi- and unistation equipment. All forms of exercise increased the metabolic rate immediately after exertion."

Elliot, Diane L.; Goldberg, Linn; Kuehl, Kerry S. (05/1992) "Effect of Resistance Training on Excess Post-exercise Oxygen Consumption." The Journal of Strength and Conditioning Research

(3) Ibid.

(4) J LaForgia, RT Withers, CJ Gore (12/24/2006) "Effects of exercise intensity and duration on the excess post-exercise oxygen consumption." PubMed

(5) "Nine recreationally active men (ranging in age from 18-35) performed the following 4 exercises for 30 minutes: a resistance training session using 75% of their 1-repetition maximum (1RM), an endurance cycling session at 70% maximum heart rate (HRmax), an endurance treadmill session at 70% HRmax, and a high-intensity interval training (HIIT) session on a hydraulic resistance system (HRS) that included repeating intervals of 20 seconds at maximum effort followed by 40 seconds of rest."

Falcone, Paul H, Et al. (03/2015) "Caloric Expenditure of Aerobic, Resistance, or Combined High-Intensity Interval Training Using a Hydraulic Resistance System in Healthy Me." The Journal of Strength and Conditioning Research